Troubleshooting A Fogatti Tankless Water Heater In Frost Protection Mode

Updated 01/22/2025 | Published 01/29/2023

Products Featured in This Question

Excel RV Tankless Water Heater - 38,000 Btu - Vent Free

(130)

$225.70

Question:

Hi! I just bought a new Fogotti water heater and it has been working fine, except it got real cold last night and now no water comes out of the hot tap in my trailer. I have cold water from the cold tap, but no water comes out the hot water side. The unit kicks on just fine in the frost protection mode, and there are no error codes. Ive tried heating up the pipes after the water heater with a hairdryer with no luck. Ive got plenty of propane, I certainly wouldve noticed if my furnace went cold last night, as it got to 10°. Im a full timer in Washington, so winterizing is not an option for me. Help!

asked by: Ellie S

Expert Reply:

RV water heaters are exposed to the outside since the only thing blocking the outside climate is just a thin metal access door with zero insulation. The Fogatti Tankless Water Heater # LSB64FR and all other brands aren't designed for use below freezing so you'll keep running into this issue unless you can find some sort of way to insulate the area around the unit outside, but would most likely run into exhaust issues.

The only way to get the unit out of frost protection mode would be to warm the pipes back up to an acceptable level and then pull the fuse located under the on/off switch on the unit for a few minutes to allow the control panel to fully reset.

Since you're full timing in a cold climate your best option would be to install a water heater like the # EX93FR, which can be inside the trailer to keep it warm enough for use. This unit isn't great for multiple points of use so if you wanted to be able to keep both units and use the # LSB64FR in warmer weather and the # EX93FR during freezing cold weather you could install a diverter for your water lines and propane line to transfer back and forth from either unit. This would be quite a bit of work but would allow you to winterize the # LSB64FR in freezing conditions.

expert reply by: Kevin C

Monty

1/9/2025

I have done all of what you mentioned and still won't operate. It reads out the water temp and will increase and decrease but won't fire up. The upper left icon pointer on remote seems to do nothing. What ya think Kevin?

Kevin C.

1/9/2025

@Monty Is the thermostat showing the water running signal when you turn the water on?

Monty

1/9/2025

@Kevin It just shows temp. No icons beneath.

Kevin C.

1/10/2025

@Monty Have you gotten any error codes? Do you have a bypass valve in your plumbing by the water heater that could've potentially be turned off, preventing water from passing through? Do you have access to the plumbing behind the water heater and can check if you hear water running from the output? When you have the water running is there a ticking noise coming from the unit? This noise is the ignitor trying to start up the unit. You could also have a faulty water flow sensor. Try releasing the pressure from the pressure and temperature release valve at the front of the unit with the hose coming down from it. You can then blow some compressed air in there and see if it ignites the exhaust. If not your sensor is bad and will need to be replaced. If that is the case you'll want to reach out to Fogatti since replacement parts can only be purchased through them.

Angela H.

1/20/2025

My hot water tank is freezing and won’t work! I have tried to contact Fogatti without success. 0/0 recommend.

Kevin C.

1/21/2025

@AngelaH I'd be happy to try and help. Starting off what is the temperature of the environment you're in? What troubleshooting steps have you already taken?

Angela H.

1/21/2025

I have mine mounted on the side of the house. It is not an RV. Do you have recommendations on buying the cover for exposed pipes?

Kevin C.

1/22/2025

@AngelaH Exposed pipes would typically just be covered with pipe insulation foam pieces from your local hardware store. It's those black foam tubes with a slit down them so you can just pop them right onto the pipe. As for the unit itself, you wouldn't really be able to insulate it or even put an enclosure around it since it would need to vent. RV water heaters unfortunately aren't designed for below freezing temperatures.